rsh(1) rsh(1)
NAME
rsh - Executes the specified command at the remote host or logs into a
remote host
SYNOPSIS
rsh [-dn] [-l user] remote_host [command] [argument ...]
The remote shell command (rsh) executes command at the remote_host, or, if
no command is specified, logs into remote_host.
FLAGS
-d Turns on socket debugging (using setsockopt()) on the TCP sockets used
for communication with the remote host.
-l user
Specifies that rsh is to log into the remote host as user instead of
the local username. If this flag is not specified, the local and
remote usernames are the same.
-n Redirects any input for rsh to the /dev/null device. Use this flag if
you are in C shell and run rsh in the background.
DESCRIPTION
The rsh command sends standard input from the local host to the remote com-
mand and receives standard output and standard error from the remote com-
mand. If you do not specify a command, rsh executes rlogin instead.
If you do not specify the -l flag, the local username is used at the remote
host. If -l user is entered, the specified username is used at the remote
host. In either case, the remote host allows access only if at least one
of the following conditions is satisfied:
+ The local user ID is not superuser, and the name of the local host is
listed as an equivalent host in the remote /etc/hosts.equiv file.
+ If either the local user ID is superuser or the check of
/etc/hosts.equiv fails, the remote user's home directory must contain
a $HOME/.rhosts file that lists the local host and username.
For security reasons, any $HOME/.rhosts file must be owned by either the
remote user or the root user, and only the owner should have Read and Write
access.
In addition to the preceding conditions, rsh also allows access to the
remote host if the remote user account does not have a password defined.
However, for security reasons, use of a password on all user accounts is
recommended.
While the remote command is executing, pressing the Interrupt, Terminate,
or Quit key sequences sends the corresponding signal to the remote process.
However, pressing the Stop key sequence stops only the local process. Nor-
mally, when the remote command terminates, the local rsh process ter-
minates.
To have shell metacharacters interpreted on the remote host, place the
metacharacters inside "" (double quotes). Otherwise, the metacharacters
are interpreted by the local shell.
EXAMPLES
In the following examples, the local host host1 is listed in the
/etc/hosts.equiv file at the remote host host2.
1. To check the amount of free disk space on the remote host host2,
enter:
$ rsh host2 df
2. To append a remote file to another file on the remote host, place the
>> metacharacters in "" (double quotes):
$ rsh host2 cat test1 ">>" test2
3. To append a remote file at the remote host to a local file, omit the
double quotes:
$ rsh host2 cat test2 >> test3
4. To append a remote file to a local file and use a remote user's per-
missions at the remote host, use the -l flag:
$ rsh host2 -l jane cat test4 >> test5
RESTRICTIONS
The rsh command is confused by output generated by commands in a .cshrc
file on the remote host. In particular, the messages, where are you? and
stty: Can't assign requested address can result if output is generated by
the startup file.
FILES
/etc/hosts.equiv
Specifies remote hosts from which users can execute commands on
the local host (provided these users have an account on the
local host).
$HOME/.rhosts
Specifies remote users that can use a local user account.
RELATED INFORMATION
Commands: rcp(1), rlogin(1), rshd(8), telnet(1).
Functions: rexec(3).
Files: rhosts(4).